US officials have charged two Chinese citizens they allege carried out an extensive hacking campaign to steal data from military service members, government agencies and private companies in the United States and nearly a dozen other countries.

Key points:

Hackers compromised the personal information of more than 100,000 navy personnel

The US Justice Department said Zhu Hua and Zhang Jianguo, acting on behalf of Beijing's main intelligence agency, were involved in computer hacking attacks on the US Navy, NASA and the Energy Department as well as companies in numerous sectors.

The defendants hacked computers to steal intellectual property and confidential business and technological data, according to the indictment.

"China's goal, simply put, is to replace the US as the world's leading superpower and they're using illegal methods to get there," FBI director Chris Wray said at a news conference.

"China's state-sponsored actors are the most active perpetrators of economic espionage."

US authorities said the two defendants, who worked in China in association with the Chinese Ministry of State Security, were charged with conspiracy to commit computer intrusions, conspiracy to commit wire fraud and aggravated identity theft.

They said the accused compromised the names, social security numbers and other personal information of more than 100,000 navy personnel.

"No country poses a broader, more severe long-term threat" to the United States than China, Mr Wray said.

The two charged men are not in custody and it is unlikely they will ever face a US court.

China urges US to withdraw charges against its citizens

China's Foreign Ministry said on Friday it resolutely opposed the "slanderous" accusations from the United States and other allies.

The United States should also withdraw charges against the two accused Chinese citizens, the ministry said.

It said China had never participated in or supported any stealing of commercial secrets and had lodged "stern representations" with Washington.

"We urge the US side to immediately correct its erroneous actions and cease its slanderous smears relating to internet security," it said, adding that it would take necessary measures to safeguard its own cybersecurity and interests.

It has long been an "open secret" that US government agencies have hacked into and listened in on foreign governments, companies and individuals, the ministry added.

"The US side making unwarranted criticisms of China in the name of so-called 'cyber stealing' is blaming others while oneself is to be blamed, and is self-deception. China absolutely cannot accept this."

US and British authorities also condemned China for violating 2015 agreements to curb cyber espionage for business purposes, slamming Chinese efforts to steal other countries' trade secrets and technologies and to compromise government computers.

"[The campaign is] one of the most serious, strategically significant, persistent and potentially damaging set of cyber intrusions against the UK and our allies that we have seen," a British security official said.

In October, the US Government charged Chinese intelligence officers with conspiring with hackers and company insiders to break into private companies' computer systems and steal information on a turbo fan engine used in commercial jetliners.

The same month, the Justice Department arrested an alleged spy for China's Ministry of State Security on charges of economic espionage and attempting to steal US aviation trade secrets.

In September, a Chinese national who had enlisted in the US Army Reserve was arrested in Chicago for working for Chinese intelligence to recruit engineers and scientists, including some who worked for US defence contractors.

Australia was among other countries also denouncing China's latest cyber attacks.

"Today, the Australian Government joins other international partners in expressing serious concern about a global campaign of cyber-enabled commercial intellectual property theft by a group known as APT10, acting on behalf of the Chinese Ministry of State Security," Foreign Minister Marise Payne and Home Affairs Minister Peter Dutton said in a statement.

Canada, Japan, the Netherlands, New Zealand and Sweden were also expected to denounce the hacking, according to a source who spoke on condition of anonymity.

"It is a sign that the United States is building an international coalition to hold China accountable for its egregious behaviour," Dmitri Alperovitch, chief technology officer of cyber security technology company CrowdStrike, said.

The Chinese embassy in Washington and NASA did not immediately respond to requests for comment.

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